Articles of produce are increasingly being individually labeled to facilitate inventory control and check-out at the grocery store. A commercially desirable method for labeling produce is to run the produce in volume through an automatic labeling apparatus, such as that described in U.S. Publication No. 2013/0011629, which applies adhesive backed labels to the articles.
The articles are carried past (typically underneath) the labeling apparatus on a conveyor in a “singulated” form, meaning that they are maintained on the conveyor in an ordered array. FIG. 1 shows an example, where articles 10 are held in respective wells 12 of a tray 14, that organizes the articles into discrete “rows” 16, and discrete “lanes” 18 on a conveyor 19. Other means for “singulating” the articles can be employed.
The lanes are defined in the direction of conveyance “R,” and the rows are perpendicular to this direction.
Automatic labeling apparatus includes one or more label-applying heads for applying labels to the articles. Typically, where the articles are singulated and therefore restricted to travel in discrete lanes, there is one label-applying head per lane, for applying labels to all the articles within that lane. In such case, the conveyor travels at a steady speed and the articles are moving as they are being labeled. This methodology provides for highest throughput.
One known alternative that can be used where high throughput is not needed employs a single label-applying head that travels across the lanes, like the raster scan in a cathode ray tube, to apply labels to all the articles within each row. In this case the conveyor advances a row of articles to the label-applying head and stops. While the conveyor is stopped, the label-applying head travels across the lanes, momentarily stopping at each article within the row to apply a label to that article. When the label-applying head has finished labeling all the articles in the row, the conveyor restarts and the process is iterated.
Each label-applying head obtains the labels it applies in sequence from a “label supply” of label webbing (or “web”) provided on a circumferentially wound “reel,” like a magnetic tape or movie film reel. The web may have a “liner,” which prevents the labels in one winding of the reel from adhering to the labels in adjacent windings. In such case, the labels must be removed at or near the label-applying head from the liner and the liner taken up and stored for ultimate discard. Alternatively, the web may be “liner-less” to avoid the need for handling and disposing of liner waste, in which case the non-adhesive side of the label is treated with an “adhesive resist” composition to perform the same function as the liner.
Each label-applying head has its own dedicated label supply. So when there are multiple label-applying heads, there are multiple label supplies that each need to be changed at periodic intervals.